As is known in the art, air traffic control (ATC) is a service that promotes the safe, orderly, and expeditious flow of air traffic. ATC services can assist in promoting safe air travel by providing information which assists in safety, preventing collisions with other aircraft, obstructions, and the ground; assisting aircraft in avoiding hazardous weather; assuring that aircraft do not operate in an airspace where operations are prohibited; and assisting aircraft in distress. ATC services can also assist in the orderly and expeditious flow of aircraft, which helps the efficiency of aircraft operations along the routes selected by the operator.
As is also known, air traffic control services are provided by air traffic control (ATC) systems. An air traffic control system typically includes a computer and display system that processes data received from air surveillance radar systems for the detection and tracking of aircraft. Air traffic control systems are used for both civilian and military applications to determine the identity and locations of aircraft in a particular geographic area.
When an aircraft is detected by an ATC radar system, information concerning the aircraft is provided to a display such that a user can look at the display and observe the position of the aircraft with respect to other aircraft as well as with respect to other moveable and non-moveable ground and air-based objects (e.g., an ATC tower, a passenger terminal, moving vehicles etc.)
Techniques for displaying the locations of aircraft and other objects on a display system are known. Such display systems, however, must be able to rapidly display a relatively large amount of information (e.g., information in maps). Furthermore, such display systems should allow a user to manipulate the information (e.g., by panning or zooming). When the information is manipulated, however, it is desirable for the display system to have a rapid real-time response.
The problem of providing rapid real-time displays of manipulated information (e.g., zoomed-in map information) is exacerbated when so-called “fill maps” (i.e., a map with fill inside a map boundary) must be shown on the display, since it is relatively difficult to rapidly fill a map boundary during a zoom or a pan operation. To address this problem, so-called “outline maps,” also known as “stroked maps,” have been used. Also, many applications, including ATC applications, have displays which include a relatively large number of images, including buttons, aircraft icons, vector displays, windows, etc., and the large number of images is difficult to rapidly display.
There is also a need to be able to rapidly display an image (e.g., a map or an aircraft image) having a relatively large amount of interactive feedback. For example, when an aircraft icon is selected, information related to that aircraft can also be displayed to the user.
Prior art display systems typically utilize stroked maps and do not generally allow rapid real-time display of maps and other display information (e.g., targets, vectors, etc.). For prior art ATC systems, it is difficult to rapidly render a display without impacting the real-time system operation of the ATC system.
Prior art attempts to provide rapid real-time display systems include systems that only partially render or re-render the display. For example, when a section of a map is selected, only that section of the display is rendered. While this approach works well when selecting only a portion of the map, it does not work well when the entire map is selected and must be re-rendered, for example when the user performs a zoom or a pan operation.
Another prior art solution that provides a real-time display uses so-called “multiple buffers” or “multiple layers.” In this approach, the display is divided into different layers (e.g., buttons are on one layer, a map background is on another layer, targets are on yet another layer, etc.). This approach works well if moving an object (i.e., an image) on only one layer because it is not necessary to re-render the other layers. This approach does not work well for pan or zoom operations, however, since in those operations, it is necessary to re-render multiple layers.
It would, therefore, be desirable to provide a display system and technique to overcome the aforesaid and other disadvantages.